A deadly knife attack in Xinjiang’s Pishan county last week, in which eight people including the three assailants were killed, has brought a wave of tightened security measures to the already tightly controlled region. (Three suspects in a previously undisclosed attack in 2015 had previously been shot dead in Pishan in January.) In Bayingolin Mongol Autonomous Prefecture, for example, all motor vehicles will have to be fitted with satellite tracking devices or be turned